Method and device for monitoring at least one activity of a connected object

ABSTRACT

A method for monitoring an activity of a connected object including a monitoring device, includes: performing, by a measurement stage of the monitoring device, a first periodic measurement of an internal signal representative of an activity of the connected object; performing, by a computation stage of the monitoring device, a first non-cryptographic computation of an activity parameter representative of the activity from the internal signal measured during the first periodic measurement; comparing, by a comparison stage of the monitoring device, between the activity parameter on completion of the first non-cryptographic computation and a range of settings of corresponding to the activity parameter; and triggering, by a control stage of the monitoring device, a safety action in response to a determination that the activity parameter is outside of the range of settings.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/183,091, filed on Nov. 7, 2018, which claims the benefit of FrenchApplication No. 1760484, filed on Nov. 8, 2017, which applications arehereby incorporated herein by reference.

TECHNICAL FIELD

Implementations and embodiments of the invention relate to the Internetof Things, commonly known to the person skilled in the art by theacronym IoT, and in particular embodiments to a method and device formonitoring at least one activity of a connected object.

BACKGROUND

In recent years, connected objects are increasingly widely used ineveryday life.

The connectivity to the Internet of a connected object advantageouslyallows a remote monitoring and control of the state of operation of theconnected object.

Increasingly, new operations are developed for dedicated connectedobjects, which demands appropriate software modifications or firmwareupgrades in these connected objects.

However, in addition to the possible existence of a security failing inthe initial version of the connected objects, such a softwaremodification or such an update via the Internet unfortunately increasesthe possibility of a modification of connected objects via malicioussoftware, even the possibility of computer hacking, which could resultin significant damage.

One conventional solution for resolving this security problem consistsin the use of a complex mechanism based on cryptographic resources, forexample a digital signature, so as to check the authorization of eachintervention on the connected objects.

However, this mechanism demands a cryptographic control circuit and aprocessing unit of high computation power, which are generally toocostly in particular for low cost connected objects.

There is thus a need to propose a technical solution with low complexityand low cost that makes it possible to monitor abnormal activities of aconnected object without using a cryptographic control circuit so as toprotect the connected object against modifications by malicious softwareor computer hacking.

SUMMARY

According to one aspect, a method is proposed for monitoring at leastone activity of a connected object. This method includes a firstperiodic measurement of a least one internal signal representative of atleast one activity of the connected object, a first non-cryptographiccomputation of at least one activity parameter representative of said atleast one activity from said at least one measured internal signal, acomparison between each computed activity parameter on completion of thefirst computation and a range of settings of the correspondingparameter, and a triggering of at least one safety action if at leastone computed activity parameter on completion of the first computationis found to be outside of said range of settings.

In practice, for a connected object intended to perform one or moremonotonic and simple operations, to draw a characteristic profileindependent of its operation but dependent on the use of its resources,for example on its power supply source or on its communication circuit,so as to create a range of acceptable profiles for determining whetherthe activity or activities of said connected object are or are notnormal.

In other words, a difference is drawn here between the operation of theconnected object and the monitoring of its activity.

The operation of the connected object is reflected in particular by thetransmission of data which are specific to the operation of the objectand its nature. Thus, a temperature sensor transmits in particular, inoperation, temperature information whereas a pressure sensor inparticular transmits pressure information.

By contrast, the monitoring of the activity of the connected object isindependent of the type of object (e.g. temperature sensor, pressuresensor, etc.) and of the type of information transmitted relating to itsoperation (e.g. temperature values, pressure values, etc.), but dealswith other parameters relating to the activity of the object (forexample frequency of the data transmission bit rate, power consumptionof the object, ranges transmitted, values aberrant, etc.) whatever thenature of the data transmitted (e.g. temperature, pressure, etc.).

Advantageously, such a method makes it possible to monitor activityparameter or parameters corresponding to the characteristic profile orprofiles of the connected object. If this or these activity parametersare detected outside of the range or ranges of settings, in other wordsthe acceptable profile ranges, the activities of the connected objectcan be considered to be abnormal and provision is made for at least onesafety action to be triggered following this detection so as to protectthe connected object.

It should be noted that the first computation uses no cryptographicresource and therefore does not require high computation power. It isadvantageously possible to adjust the period of the first computation asa function of the frequency of activity of the connected object so as tofurther balance its performance and its energy/power consumption.

According to one implementation, each activity parameter includes apower consumption parameter and/or a data transmission parameter.

It should be noted that the power consumption parameter or the datatransmission parameter of the connected object depends on the rate andthe intensity of activities of the connected object but does not dependon its operation or operations.

As a non-limiting example, the power consumption parameter can be aparameter chosen from the group formed by the following parameters:average power consumption, average current and peak current value; andthe data transmission parameter can be a parameter chosen from the groupformed by the following parameters: size of packets, transmission bitrate and communication model.

According to one implementation, each safety action is chosen from thegroup formed by: a cutting of power supply to the connected object, areset of default parameters, and a transmission of notification signalsto a computer server via a communication link.

As an indication, the communication link can for example be based on atechnology chosen from the group formed by the following technologies:Long Range Lowe Power (LoRa), SigFox, mobile telephony network, WiFi andEthernet.

According to one implementation, the range of settings of each activityparameter can be predetermined, for example preconfigured by themanufacturer of the connected object.

According to another implementation, the range of settings of eachactivity parameter is intended to be updated in a learning phase.

This learning phase advantageously allows a user of the connected objectto assist the connected object either in spontaneously refining theactivity parameters, or in readapting the activity parameters to apossible upgrade of firmware contained in the connected object.

The learning phase can for example include a second periodicmeasurement, under authorization of a user of the connected object, ofsaid at least one internal signal during a predetermined oruser-configurable period, a second non-cryptographic computation of saidat least one activity parameter from said at least one internal signalmeasured during said period, and an update of the range of settings ofthe corresponding activity parameter from each computed activityparameter on completion of the second computation.

According to another aspect, a connected object is proposed including adevice for monitoring at least one activity of the connected object.

Said monitoring device includes a measurement stage configured toperform a first periodic measurement of at least one internal signalrepresentative of said at least one activity of the connected object, acomputation stage configured to perform a first non-cryptographiccomputation of at least one activity parameter from said at least onemeasured internal signal, a comparison circuit configured to compareeach computed activity parameter and a range of settings of thecorresponding activity parameter, and a control stage configured totrigger at least one safety action if at least one computed activityparameter is found to be outside of said range of settings.

According to one embodiment, each activity parameter includes a powerconsumption parameter and/or a data transmission parameter.

As a non-limiting indication, the power consumption parameter can be aparameter chosen from the group formed by the following parameters:average power consumption, average current and peak current value.

The transmission parameter can for example be a parameter chosen fromthe group formed by the following parameters: size of data packetstransmitted, transmission bit rate and communication protocol.

According to one embodiment, each safety action is chosen from the groupformed by: a cutting of power supply to the connected object, a reset ofdefault parameters, and a transmission of notification signals to acomputer server via a communication link.

The communication link can for example be based on a technology chosenfrom the group formed by the technologies: LoRa, SigFox, mobiletelephony network, WiFi and Ethernet.

According to another embodiment, the connected object further includes aprocessing circuit configured to generate information resulting from theoperation of the connected object and a communication circuit configuredto transmit this information outside of the connected object over saidcommunication link.

As indicated above, the functionality of the monitoring device isdifferent from that of the processing circuit.

The monitoring device can for example be incorporated in software moduleform in a non-modifiable program memory of the processing circuit.

Such software is then advantageously protected.

According to a variant, the monitoring device is incorporated in amicrocontroller, for example of STM8® type, marketed by the companySTMicroelectronics, configured to receive at least a part of theinformation transmitted by the processing circuit for monitoringpurposes. The microcontroller includes an execution program stored in anon-modifiable program memory and has no link with the communicationcircuit.

According to another variant, the monitoring device is coupled to thecommunication circuit so as to transmit the notification signals oversaid communication link.

According to one embodiment, the range of settings of each parameter ispredetermined.

According to another embodiment, the monitoring device is configured toupdate the range of settings of each activity parameter in a learningphase.

As a non-limiting indication, in the learning phase, the measurementstage is configured to perform a second periodic measurement, underauthorization of a user of the connected object, of said at least oneinternal signal during a predetermined or user-configurable period, thecomputation stage is configured to perform a second non-cryptographiccomputation of said at least one activity parameter from said at leastone internal signal measured during said period, and the control stageis further configured to update the range of settings of thecorresponding activity parameter from each computed activity parameteron completion of the second computation.

According to another aspect, a monitoring device is proposed that isincorporated in a connected object as defined above.

According to yet another object, an electronic system is proposedincluding one or more connected objects as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features of the invention will become apparent onstudying the detailed description of non-limiting implementations andembodiments, and the attached drawings in which:

FIGS. 1 to 5 schematically illustrate implementations and embodiments ofthe invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Implementations and embodiments of the invention relate to the Internetof Things, commonly known to the person skilled in the art by theacronym IoT, and more particularly the objects connected to the Internetnetwork in the broad sense, that is to say including for example thelocal area network (LAN), the wide area network (WAN), intended tomutually communicate computer data and to carry out practical andrelatively simple operations, such as connected temperature sensors,connected door opening sensors and connected electrical switches.

The reference 1 in FIG. 1 designates an electronic system, here, forexample, a set of connected objects known as “Internet of Things” (IoT)intended to ensure the home automation safety of a dwelling such as ahome or an office.

This system 1 includes several so-called connected objects, here, forexample a connected smoke sensor 2, a door opening sensor 3 and atemperature sensor 4.

This system 1 further includes a gateway PSR known to the person skilledin the art and intended to manage the sensors 2 to 4.

These sensors 2 to 4 are connected to the Internet, for example via aWi-Fi communication circuit, MCWF, conforming to the IEEE 802.11standards, incorporated in the system 1.

Because of this, the system 1 allows its user to remotely check, forexample via a software application for smartphones, the state ofoperation of each sensor 2 to 4, to receive one or more warnings via theInternet in the presence of an abnormal value detected by one of thesensors 2 to 4, for example smoke detected in the ambient air inproximity to the connected smoke sensor 2, and to remotely controloperations of each sensor 2 to 4.

It should be noted that the sensors 2 to 4 are intended here to performrelatively regular and simple operations. In other words, there is noneed to have complex processing circuit or high computation power.

These sensors 2 to 4 are consequently designed to be manufactured at lowcost and therefore include no costly cryptographic control circuitaiming to avoid non-authorized interventions.

For simplification purposes and as a non-limiting example, reference isnow made to FIG. 2 to illustrate an example of production of thetemperature sensor 4.

The temperature sensor 4 includes detection circuit 5 configured todetect one or more temperatures in proximity to a temperature sensor 4,processing circuit 6 configured to receive the detected temperatures andto generate information resulting from the operation of the sensor 4,here temperature detection values and any warnings if these detectionvalues exceed setting thresholds, communication circuit 7 configured totransmit these detection values to a computer server 8 via acommunication link LC so as to allow one or more users of the sensor 4to consult these detection values and receive any warnings, a monitoringdevice 9 configured to monitor activity parameters PA of the sensor 4such as a transmitted data bit rate, a size of data packets transmitted,an average current, the peak value of a current, and an average powerconsumption, and a power supply source SA.

As indicated above, the operations performed by the temperature sensor4, here to regularly sense the temperature in proximity to thetemperature sensor 4, are relatively regular and simple and do notrequire costly cryptographic control.

Consequently, the activity parameters PA of the sensor 4 which do notdepend on these operations themselves but depend on activities of thesensor 4 to perform these operations are also supposed to be regular andstable when the sensor 4 is in its normal state.

In other words, if the temperature sensor 4 operates normally, theactivity parameters PA, here for example the average power consumptionand the data transmission bit rate of the sensor 4, are normally alwayswithin predictable ranges of values that can be predetermined, forexample in the manufacturing of the sensor 4.

When the sensor 4 is subjected to computer hacking or is modified viamalicious software, such malicious activity may manifest itself asmodification of the activity parameters PA so as to be outside ofpredictable ranges of values, or ranges of settings.

For example, the average power consumption of such a hacked sensor 4 andits data transmission bit rate will be increased for at least a certaintime following such a computer hacking.

Because of this, it is possible to monitor the correct operation of thetemperature sensor 4 via regular tracking of these activity parametersPA.

It should be noted that FIG. 2 illustrates, in effect, an example ofproduction of the temperature sensor 4 in which the monitoring device 9is physically coupled (e.g. within the sensor 4) to the processingcircuit 6, to the communication circuit 7 and to the power source SA.

The monitoring device 9 is configured to receive a temperaturemeasurement signal SM delivered by the processing circuit 6 and acurrent signal SC delivered by the power source SA.

More particularly, according to this embodiment, the monitoring device 9is intended to transmit to the computer server 8 one or morenotification signals SN via the communication circuit 7 and thecommunication link LC when the activity or activities of the sensor 4are considered to be abnormal by the monitoring device 9.

As a non-limiting indication, the communication link LC is based on atechnology chosen form the group formed by the following technologies:LoRa, SigFox, mobile telephone network, WiFi and Ethernet.

The computer server 8 can be located locally in the system 1 (notillustrated in FIG. 2) or, advantageously, remotely on a “Cloud”.

When the computer server 8 receives the notification signal or signalsSN, the computer server 8 is configured to send a warning to the defaultuser of the system 1 and to ask the user for authorization to cut thepower supply to the sensor 4 or to upgrade firmware contained in thesensor 4.

Reference is now made to FIG. 3 to schematically illustrate anotherexample of production of the monitoring device 9 and its internalstructure.

In this variant, the monitoring device 9 is implemented in the form of asoftware module incorporated in the processing circuit 6, here forexample a microcontroller of STM32® type marketed by the companySTMicroelectronics.

In order to ensure that the monitoring device 9 is not modified, forexample by malicious software, it is recommended to isolate thismonitoring device 9.

In this respect, it is preferable to implement the software module in anon-modifiable medium, for example a non-modifiable flash memory MM.

The monitoring device 9 here includes a measurement stage or circuit 10,a computation stage or circuit 11, a comparison stage or circuit 12 anda control stage or circuit 13.

As an indication but in a non-limiting manner, the activity parametersPA to be monitored by the monitoring device 9 include power consumptionparameters PC such as the average power consumption, the average currentand the peak current value; and transmission parameters PT such as thesize of packets transmitted, the transmission bit rate and thecommunication protocol.

The measurement stage 10 is configured to perform a first periodicmeasurement of at least one internal signal representative of at leastone activity of the sensor 4, here for example the measurement signal SMrepresentative of the data transmission bit rate DT and the currentsignal SC of the power source SA representative of the peak currentvalue CC.

It should be noted that these activity parameters DT and SA are drawnfrom the technical characteristics of the measurement signal SM and ofthe current signal SC but not from information contained in themeasurement signal SM and the current signal SC.

Based on the technical characteristics of the sensor 4, it is possibleto predetermine a range of settings of the transmission bit rate DTR,for example<100 MB/s, and a range of settings of the peak current valueCCR, for example<200 mA.

In order to minimize its influence on the performance of the sensor 4,the first measurement can for example be performed every 8 hours.

The computation stage 11 is coupled to the measurement stage 10 andconfigured to perform a first non-cryptographic computation from themeasurement signal SM and the current signal SC so as to obtain thecomputed transmission bit rate DTC and the computed peak current valueCCC.

Advantageously, a high computation power for performing the firstnon-cryptographic computation is not necessary which therefore haslittle influence on the performance of the sensor 4.

The comparison stage 12 is configured to compare the computed activityparameters DTC and CCC and the ranges of settings of the correspondingactivity parameters DTR and CCR.

If the computed activity parameters DTC and CCC are found respectivelyto be in their range of settings that indicates that the sensor 4 isoperating in its normal state and that there is no abnormal activity tobe signaled.

Otherwise, the activity of the sensor 4 is different in relation to itsnormal state and the sensor 4 has potentially undergone a computerhacking.

Consequently, the control stage 13 is configured to trigger at least onesafety action, here for example a cutting of the power supply CA to thesensor 4 and a reset of default parameters RP so as to avoid other moresignificant damage.

It should be noted that these safety actions CA and RP are also providedin the embodiment of the monitoring device 9 illustrated in FIG. 2.

According to a preferred embodiment illustrated in FIG. 4, themonitoring device 9 is incorporated in a microcontroller MC, for exampleof the type STM8® marketed by the company STMicroelectronics, receivingthe measurement signal SM and the current signal SC.

The monitoring device 9 here includes an execution program stored in anon-modifiable program memory MP and has no physical or communicativelink with the communication circuit 7.

In other words, the monitoring device 9 and its program memory MP areprotected against any modifications via malicious software or computerhacking and are not modifiable via the processing circuit 6 or thecommunication circuit 7.

In this embodiment, the safety actions provided by the monitoring device9 include the cutting of power supply CA to the sensor 4 and theresetting of parameters RP but not the transmission of notificationsignals SN.

As mentioned before, the embodiment of the monitoring device 9illustrated in FIG. 2 possibly provides an update of firmware containedin the sensor 4.

Reference is now made to FIG. 5 to schematically illustrate an exampleof implementation of such an upgrading of the firmware.

If the user authorizes said upgrade in step ETP1, the computer server 8is configured to control the processing circuit 6 so as to download anew version of the firmware in step ETP2 via the communication circuit7.

Once the new version of the firmware is downloaded in step ETP3, theprocessing circuit 6 is configured to perform the upgrading of thefirmware in step ETP4 with this latest version of the firmware.

Since the new version of the firmware possibly provides new operationsand new configurations of the sensor 4, the monitoring device 9 isfurther configured to start an update in step ETP5 of the ranges ofsettings of each activity parameter DTR and CCR in a learning phase PAfollowing said upgrading of the firmware.

It should be noted that the user of the sensor 4 can also launch thelearning phase PA without an upgrading of the firmware so as to assistthe sensor 4 in spontaneously refining its activity parameters DT, SA.

During this learning phase PA, the measurement stage 10 is configured toperform a second periodic measurement in step ETP6, under authorizationof the user of the sensor 4, of the measurement signal SM representativeof the transmission bit rate DT and of the current signal SC of thepower source SA representative of the peak current value CC.

This second measurement in step ETP6 has, for example, a sameperiodicity as that of the first measurement, and the duration of thissecond measurement in step ETP6 can be predetermined, for example equalto 24 hours, or configurable by the user of the sensor 4, in other wordsthe user can place a term on the second measurement when he or shewants.

The computation stage 11 is further configured to perform, during saidperiod of the second measurement, a second non-cryptographic computationin step ETP7 from the measurement signal SM and the current signal SC soas to obtain a new computed transmission bit rate NDTC and a newcomputed peak current value NCCC.

The control stage 13 is further configured to update in step ETP8 theranges of settings of each parameter DTR and CCR from the new computedtransmission bit rate NDTC and from the new computed peak current valueNCCC.

The monitoring device 9 is configured to continue the monitoring of atleast one activity in step ETP9 of the sensor 4 with said updated rangesof settings.

It should be noted that this learning phase is not necessary forconnected objects which do not need upgrading for security reasons, suchas connected pacemakers and connected insulin pumps.

Thus, a device for monitoring at least one activity of a connectedobject is obtained that offers a low cost and low complexity securitymechanism.

This security mechanism advantageously allows a physical and/orcommunicative division between this monitoring device and processing andcommunication circuits of the connected object so as to reinforce thesecurity (e.g. rendering the monitoring device non-modifiable via theprocessing and/or communication circuits), and a learning mode adaptedto any upgrading of the firmware of the connected object.

What is claimed is:
 1. A method for monitoring an activity of a connected object comprising a monitoring device, the method comprising: having an execution program of the monitoring device in a non-modifiable memory of a microcontroller; performing, by a measurement stage of the monitoring device, a first periodic measurement of an internal signal produced by a processing circuit, the internal signal being representative of an activity of the connected object; performing, by a computation stage of the monitoring device, a first non-cryptographic computation of an activity parameter representative of the activity from the internal signal measured during the first periodic measurement; comparing, by a comparison stage of the monitoring device on completion of the first non-cryptographic computation, between the activity parameter and a range of settings of corresponding to the activity parameter; and triggering, by a control stage of the monitoring device, a safety action in response to a determination that the activity parameter is outside of the range of settings.
 2. The method according to claim 1, wherein the activity parameter comprises a power consumption parameter or a data transmission parameter.
 3. The method according to claim 2, wherein the power consumption parameter comprises at least one of an average power consumption of the connected object, an average current of the connected object, and a current peak value of the connected object, and wherein the data transmission parameter comprises at least one of a size of data packets transmitted by the connected object, a transmission bit rate of the connected object, and a communication protocol executed by the connected object.
 4. The method according to claim 1, wherein the safety action comprises at least one of a cutting of a power supply of the connected object, a reset of default parameters of the connected object, and a transmission of a notification signal to a computer server communicatively coupled to the connected object via a communication link.
 5. The method according to claim 4, wherein the communication link is based on a technology chosen from at least one of LoRa, SigFox, mobile telephony network, Wi-Fi and Ethernet.
 6. The method according to claim 1, wherein the range of settings of the activity parameter is predetermined, static during operation of the connected object, or both predetermined and static during operation of the connected object.
 7. The method according to claim 6, wherein the range of settings of the activity parameter is updated during operation of the connected object in a learning phase.
 8. The method according to claim 7, wherein the learning phase comprises a second periodic measurement by the measurement stage of the connected object under authorization of a user of the connected object of the internal signal during a predetermined period, or a user-configurable period; a second non-cryptographic computation by the computation stage of the connected object of the activity parameter from the internal signal measured during the predetermined period or the user-configurable period; and updating the range of settings corresponding to the activity parameter from the activity parameter on completion of the second non-cryptographic computation.
 9. The method according to claim 1 wherein the processing circuit is configured to generate information resulting from an operation of the connected object and a communication circuit is configured to transmit the information outside of the connected object over a communication link.
 10. The method according to claim 9, further comprising isolating the execution program from the communication circuit and the processing circuit.
 11. The method according to claim 9, further comprising coupling the monitoring device with the communication circuit to transmit a notification signal that comprises the safety action.
 12. A connected object comprising: a microcontroller configured to execute a program stored in a non-modifiable memory of the microcontroller to cause the microcontroller to operate as follows: perform a first periodic measurement of an internal signal, received from a processing circuit representative of an activity of the connected object; perform a first non-cryptographic computation of an activity parameter from the internal signal measured during the first periodic measurement; compare the activity parameter and a range of settings corresponding to the activity parameter; and trigger a safety action in response to the activity parameter being outside of the range of settings.
 13. The connected object according to claim 12, wherein the activity parameter comprises a power consumption parameter or a data transmission parameter.
 14. The connected object according to claim 13, wherein the power consumption parameter comprises at least one of an average power consumption of the connected object, an average current consumed by the connected object, and a peak current value of the connected object, and wherein the data transmission parameter comprises at least one of a size of data packets transmitted by the connected object, a transmission bit rate of the connected object, and a communication protocol executed by the connected object.
 15. The connected object according to claim 12, wherein the safety action comprises at least one of a cutting of power supply to the connected object, a reset of default parameters of the connected object, and a transmission of a notification signal to a computer server communicatively coupled to the connected object by a communication link.
 16. The connected object according to claim 15, wherein the communication link is based on a technology chosen from at least one of LoRa, SigFox, mobile telephony network, WiFi and Ethernet.
 17. The connected object according to claim 12, wherein the safety action comprises transmission of a notification signal to a computer server communicatively coupled to the connected object by a communication link, the processing circuit is configured to generate information resulting from an operation of the connected object, and a communication circuit is configured to transmit the information outside of the connected object over the communication link.
 18. The connected object according to claim 17, wherein the processing circuit is coupled to the communication circuit so as to transmit the notification signal over the communication link.
 19. The connected object according to claim 17, wherein the program is isolated from the communication circuit and the processing circuit.
 20. The connected object according to claim 17, wherein the microcontroller is coupled with the communication circuit to transmit the notification signal.
 21. The connected object according to claim 12, wherein the range of settings of the activity parameter is predetermined, static during operation of the connected object, or predetermined and static during operation of the connected object.
 22. The connected object according to claim 12, wherein the microcontroller is configured to execute the program stored in the non-modifiable memory to update the range of settings of the activity parameter during operation of the connected object in a learning phase.
 23. The connected object according to claim 22, wherein, in the learning phase the microcontroller executes the program to cause the microcontroller operate as follows: perform a second periodic measurement, under authorization of a user of the connected object, of the internal signal during a predetermined period or a user-configurable period; perform a second non-cryptographic computation of the activity parameter from the internal signal measured during the predetermined period or the user-configurable period; and update the range of settings corresponding to the activity parameter from the activity parameter on completion of the second non-cryptographic computation. 